Pneumatic driving gear



1967 KENICHLTAKAHATA 3,354,787-

PNEUMATIC DRIVING GEAR Filed Oct. 25, 1965 2 Sheets-Sheet 1 49 25 /0 5 /4 05 INVENTbR 5y 7 J56 8- I 57 BY LUM ZQJMfM ATTORNEY S 1967 KENICHI TAKAHATA PNEUMATIC DRIVING GEAR 2 Sheets-Sheet 2 Filed Oct. 25, 1965 mm wm QM M & mm m 6 w W Qw mm a g Y \N M,\ g N m X7 Q R hm. WM QR Q g Q N g Q Q Q NM, Q a N Q m, w

United States Patent 3,354,787 PNEUMATIC DRIVING GEAR Kenichi Takahata, 84 3 Todoroki, Tamagawa, Setagaya-ku, Tokyo, Japan Filed Oct. 25, 1965, Ser. No. 505,183 Claims priority, application Japan, Oct. 24, 1964, 39/60,??61, 39/831,276 1 Claim. (Cl. 91222) ABSTRACT OF THE DISCLOSURE A driving gear for driving an output motion rod, comprising a piston having an annular channel in the circumference thereof and a valve chest therein, a valve body having front and rear valves and disposed in said valve chest, said valve body being in communication with said annular channel, a cylinder having an inwardly opening bypass air passageway, an air inlet and an exhaust in suitable locations thereof, said piston having an air communication hole in the rear portion thereof communicating said valve chest with the rear portion of said cylinder, said piston being slidably fitted in said cylinder, an output motion rod fixed to the front face of said piston and a spring interposed between said front face of said piston and the end of the cylinder opposed thereto in such a manner that said output motion rod projects outwardly of said end of said cylinder, whereby when air under pressure is supplied through said air inlet so as to move the piston and output rod against the spring, exhaust of the air causes the output motion rod to be retracted by means of the spring.

This invention relates to a pneumatic driving gear.

It is an object of the present invention to provide a novel pneumatic driving gear in which vertically or horizontally reciprocative or circular movement can be obtained by continuously blowing in .air under pressure higher than the atmospheric pressure.

It is a further object of the invention to provide a novel pneumatic driving gear which is attached to a garage jack so that the load carrier can be operated by utilizing high pressure air from the air pump without requiring the use of manpower.

It is still a further object of the invention to provide a novel pneumatic driving gear which can operate a garage jack or the like in a limited space.

The invention will be described in detail by way of example with respect to the accompanying drawings, wherein:

FIG. 1 is a schematic view illustrating the fundamental principle of the present invention;

FIG. 2 is a longitudinal cross-section showing an example of the driving gear according to the present invention;

FIG. 3 is a partial cross-sectional view showing the major portions of the roundabout air passageway and the piston rings;

FIG. 4 is a longitudinal cross-section illustrating the oil supply cylinder attached to the front portion of the driving gear;

FIG. 5 is a cross-sectional view showing the cylinder of FIG. 4 as it is actuated; and

FIG. 6 is a view showing, partially in cross-section, and generally on a different scale, the driving gear used with .a garage jack.

The device of the presentinvention is fundamentally an air pump driven by air pressure as schematically illustrated in FIG. 1, said air pump comprising a piston E adapted to advance by air pressure against the action of a resilient member D, in a cylinder C having an air inlet A and an exhaust port B, and having an auxiliary piston F fixed to said piston E so as to move forward and backward in an oil supply cylinder G with said piston E thereby achieving the driving operation.

Referring now to FIGS. 2 to 5 of the drawings, there is shown a first cylinder 2 having an air inlet 1. A cylindrical portion 3 of said first cylinder 2 is formed with a thick portion 4 in a suitable place thereof, said thick portion 4 being provided with a bypass air passageway 5. A piston 6 is slidably disposed in said first cylinder 2, and this piston 6 has a slightly reduced diameter between piston rings 7 and 8 thereon so as to form an annular channel 9. Said annular channel 9 is connected with two valve chests such as fore and rear valve chests 10, 11 formed in the forward center portion of the piston 6, by means of a connecting bore 12. In the rear portion of said piston 6 is a valve body 13 integrally secured thereto, said valve body being provided with an air communication hole 14. Said valve body 13 is also formed with a valve seat 15 in the rear portion and another valve seat 16 in the center portion. Further, the valve body 13 is provided with an air exhaust hole 18 communicating with a space 17 in front of the piston 6. A main valve 20 formed integrally with a valve rod 22 is disposed in the front portion 19 (best shown in FIG. 5) of the valve chest 10 in such a manner that a rubber valve 21 is urged in contact with the rear portion of said rear valve chest 11.

In the fore portion of the first cylinder 2 there is provided a fore cylinder partition wall 23 having an annular channel 24, and a spring 26 is interposed between said annular channel 24 and a recess 25 formed in the front surface of the piston 6. Thus, the piston 6 is maintained in such a state that it is always forced against the rear portion of the cylinder 2 by means of said spring 26. A rod 27 having one of its ends projected and fixed in the recess 25 in the front surface of the piston 6 and serving as an output motion rod is axially slidably extended through a second cylinder 29 which is provided with a packing 28 therein adjacent the inner or rear end and which is fitted in the central opening formed in the partition wall 23 in opposed relationship to said recess 25.

An air exhaust hole 30 is formed in the cylindrical wall of the cylinder 2 intermediate the lower end of the partition wall 23 and the ring 7 of the piston 6 when the piston is in its fully extended position as shown in FIG; 5. Numeral 31 indicates a stopper formed in the rear end portion of the valve rod 22 behind the rubber valve 21.

In the operation of the device of the present invention, air under high pressure continuously blown into the cylinder 2 through the air inlet 1 gOeS into a rear chamber 40 isolated in the cylinder 2 by the piston ring 8 so that the piston 6 is moved forward to thereby cause the piston ring 8 to open the entrance of the bypass air passageway 5, as illustrated in FIG. 5. From the thus opened entrance the air passes through said bypass air passageway 5 and further through the annular channel 9 between the piston rings 7 and 8 into the connecting bore 12. The air passing through the connecting bore 12 now forces the front face 41 of main valve 20 backwardly in the valve chest 10 until the back face 42 of the main valve 20 comes into contact with the valve seat 1 6 (see FIG. 5). This contact of the main valve 20 with the valve seat 16 causes the backward movement of said main valve 20 to be discontinued. Thereupon, the air communication hole 14,

I through the air exhaust hole 18 so as to be finally exhausted through the exhaust hole 30. The air pressure against the back surface 43 of the rubber valve 21 is the same as that against the front surface 41 of the main valve 20, while the main valve 20 has a much greater size than said back surface 43.01": the rubber valve 21. Due to this greater-size of main valve 20, the air pressure from the connecting bore 12 can be applied to the front surface of the main valve so that the main valve 20 and the rubber valve 21 ,are readily moved so as to disengage the rubber valve 21 from the valve seat 15. As soon .as the valve 21 is disengaged from the valve seat 15, the air under high pressure is exhausted through the air exhaust holes 18 and 30 so that the pressure in the rear chamber 40 behind the piston 6 is decreased, and therefore the piston 6'is moved backwardly in the first cylinder 2 by the resilient force of the spring 26 and the stopper 31 strikes the back 'wall 44 of the first cylinder 2 while .the valve seat advances in the valve chamber 10 toward abutment 44 until it contacts the rubber valve 21. At. this moment, namely, when the .piston 6 is returned in the first cylinder 2 by the resiliency of the spring 26 and the stopper 31 touches the abutment 44 on back wall .35 of. said cylinder 2 ,as described above and shown in FIG. 2, the compressed air in the connecting bore 12 of .the annular channel 9 and in the valve chest 10 in front of the main valve temporarily fails to escape and remains therein because the distance between the piston rings 7 and -8 is made slightly greater than that between the inlet and outlet of the bypass air passageway 5, and said compressed air thus temporarily remaining in the connecting bore 12 and in the valve chest 10 serves to prevent any sudden contact between the front surface 19 of the valve chest and the front surface 41 of the main valve when the piston 6 is moved in the first cylinder 2.

Numeral 32 indicates an attaching member for mounting by means of a bolt 33 the partition wall 23 projecting forwardly from the cylinder 2. Numeral 34 represents a washer for said bolt 33, and numeral 35 is a rear partition wall provided with the air inlet 1. This rear partition wall 35 is fixed by a bolt 39 extending through a rear flange portion 36 of cylinder 2, a flange portion 37 of said rear partition wall 35 and a washer 38.

In this manner the piston 6 in the cylinder 2 continues to move forward and backward at high velocity, and accordingly the output motion rod 27 fixed in the center portion of the front surface of the piston '6 also moves forward and backward.

In the pneumatic driving gear of the present invention, it will be noted that when air under pressure higher than atmospheric pressure is continuously blown in through the air inlet, the operation as heretofore described is effected by the actuations of the piston 6, the bypass air passageway '5, the piston rings 7, 8, the main valve 20, the rubber valve 21, etc. provided within the first cylinder 2, and thus the piston 6 is axially reciprocated within the cylinder 2. Further, the velocity at which the piston 6 is reciprocated .can be selected as desired by varying the pressure of the air to be blown in. Furthermore, power can be obtained by actuating the rod 27 fixed to the front face of the piston 6 so as to cause it to move outwardly of the second cylinder 29 and transmitting the resulting reciprocative motion of the rod 27 through a suitable means such as'a crank, that is, the rod 27 as an output motion rod is operable as a power rod. Therefore, the driving gear of this invention utilizing air is particularly suitable for civil engineering works and works in headways'where motors, internal combustion enginees and the like cannot be used. In addition, the pneumatic driving gearof the present invention, which is compact and simple in structure but relatively great in output, can be used in a narrow place, and it also can actuate various machines without causing any trouble.

The shown and described embodiment of the present invention is used with a garage jack.

The vertically moving control column type oil supply apparatus of the prior art is a lever type hydraulic apparatus, and such type of apparatus requires a number of vertical movements of the control column and consequently much time to lift the load to a desired level. Additionally, the vertical movement of the control column requires manpower exclusively, while such manual operation of the control column tends to exhaust the operator before he starts repair .of the automobile and the like work. Another disadvantage of this type of apparatus is that great diificulty is often experienced in vertically moving the control column in a narrow or limited space. Therefore it is impossible to use a jack at a desired loading point of the automobile body, and in the event that repair is to be made by elevating a part of the car body remote from the part to be repaired, it is often difiicult to have the part of the body to be repaired elevated .up to a desired level sufiicient to effect the repair. In such cases it has usually been practiced to obtain a desired elevation of the body by applying connector means to the jack.

Referring to FIG. 6 of the drawings, there is shown an embodiment using the driving gear of the present invention with a garage jack. In this embodiment, oil is supplied under pressure into an oil cylinder 45 of a garage jack 66 so as to actuate a load carrier 46. Numeral 2 is the previously described first cylinder of the pneumatic driving gear for supplying oil under pressure into said oil cylinder 45. The first cylinder 2 is mounted in order to force oil into the oil cylinder 45 of the garage jack 66, and then compressed air is continuously blown into said first cylinder 2 from the outside so as to push the piston 6 having the piston rings 7, 8 fitted thereto until said piston 6 reaches the partition wall 23 located forwardly of the first cylinder 2. The air enters the roundabout air passageway 5 as the piston ring 8 passes the entrance 47 of said roundabout air passageway, and the air then reaches the front surface 19 of the fore valve chest 10 through the annular channel 9 between the two piston rings 7 and 8 and the communication hole 12. The air reaching the front surface 19 now forces the front surface 41 of the main valve 20 backwardly through said front surface 19 of the valve chest 10 and enters said valve chest'10 to move the main valve 20 backwardly insaid valve chest 10 until the back surface of the main valve20 comes into contact with the valve seat 16. Upon contact of the main valve20 with the valve seat 16, the movement of the main valve is stopped while the air communication hole 14 which has been closed is now opened, and through this opened air communication hole 14 the compressed air flows into the valve chest 11, and then enters the chambers or space in front of the piston 6 through the air exhaust hole 18. Thereafter the air is exhausted exteriorly through the air exhaust hole 30. Thereupon, the piston 6 is forced back to its original position by the resilient force of'the spring 26 disposed in the first cylinder 2 between the front face '17 of the piston 6 and the partition wall 23 of said first cylinder 2, and the piston 6 is again moved forwardly by the continuously blown-in compressed air. Thus the piston 6 repeats its forward and backward movement. Simultaneously with the movement of the piston 6, the rod 27 also moves forward and backward since the rodis integrally attached to the piston .6 in such a manner as to slide in the oil supply cylinder 48 fixed to the partition wall 23 of the first cylinder 2. Oil admitted througha check valve 49 due to the retraction of the rod 27 is forced through a a check valve 50 into the oil cylinder 45 for elevating the garage jack upon the advance of the rod 27 so as to push the rear end portion 56 of the piston 55 having the rear end portion 51 of the'load carrier 46 connected with shafts 53 and 54 by a connecting plate 52, and thereby the piston 55 is moved forward and simultaneously the load carrier 46 is also moved upwardly by the connectingplate 52 into a position as indicated by'the chain line in FIG. 6. And in downwardly moving the piston 55, oil in the rear portionof oil cylinder 45 is returned into an oil chamber 57 by suitably releasing from the outside a threaded shaft 60 pressing a ball valve 59 interrupting the intermediate portion of a connecting hole 58 connecting the oil cylinder 45 with the oil chamber 57 so as to disengage said ball valve 59 from the valve seat 61. Subsequently the oil passes through oil passageway 62 to enter the space in front of a forwardly and backwardly movable sealing shield plate 63 fixed to the rear portion 56 of piston 55 thereby gradually lowering the piston 55.

In other words, the forward and backward movement of the piston 6 is effected at a high velocity by the pressure of the air blown into the first cylinder 2 While the oil is rapidly forced into the oil cylinders 45 and 66 by the movement of rod 27 sliding forwardly and backwardly in the oil supply cylinder 48 cooperating with the piston 6.

Thus, air under constant high pressure is blown into the air pump to actuate the piston 6 at a high velocity and thereby cause the cooperative rod 27 to slide in the oil supply cylinder 48 so as to introduce the oil from the oil chambers 57 and 70 and force the oil into the oil cylinder 45 thereby actuating the piston 55. Upon actuation of the piston 55, the load carrier 46 on the loading arm supporting a body of an automobile at predetermined portions thereof are raised to a desired level, and when the desired level is once reached, the supply of air into the first cylinder is stopped. When air is no longer supplied, flow of oil into the oil cylinder 48 is also stopped with any back flow of oil being effectively prevented by the check valve, and the jack remains stationary at the desired level with the load thereon. When the work such as repair of the car, oil filling, washing or the like has been finished, the piston 55 is quietly retracted, as previously described, by opening the above illustrated ball valve 59 so as to quietly lower the load. This is done in the same manner as in a garage jack or portable jack of the prior art.

Further, it is possible to use an oil supply device 65 having a conventional type of vertically movable control column attached thereto, instead of the heretofore described oil supply device, with the air pump of the present invention.

While a preferred embodiment of the present invention has been described and shown in detail, it should be noted that various parts of the construction can be modified without departing from the spirit and scope of the appended claim.

What I claim is:

A driving gear for driving an output motion, rod, comprising a piston having an annular channel in the circumference thereof and a valve chest therein, a valve body having front and rear valves and disposed in said valve chest, said valve body being in communication with said annular channel, a cylinder having an inwardly opening bypass air passageway, an air inlet and an exhaust in suitable locations thereof, said piston having an air communication hole in the rear portion thereof communicating said valve chest with the rear portion of said cylinder, said piston being slidably fitted in said cylinder, an output motion rod fixed to the front face of said piston and a spring interposed between said front face of said piston and the end of the cylinder opposed thereto in such a manner that said output motion rod projects outwardly of said end of said cylinder, whereby when air under pressure is supplied through said air inlet so as to move the piston and output rod against the spring, exhaust of the air causes the output motion rod to be retracted by means of the spring.

References Cited UNITED STATES PATENTS 1,031,340 7/1912 Howard 91224 2,039,895 5/1936 Green 52 X 2,145,014 1/1939 Rosenberry 6052 X 2,573,993 1 1/ 1951 Sedgwick 6051 2,938,347 5/1960 Sturgis 6052 EDGAR w. GEOGHEGAN,Prima1-y Examiner. 

